BASE-PAIRING INTERACTIONS INVOLVING THE 5' AND 3'-TERMINAL NUCLEOTIDES OF GROUP-II SELF-SPLICING INTRONS
BASE-PAIRING INTERACTIONS INVOLVING THE 5' AND 3'-TERMINAL NUCLEOTIDES OF GROUP-II SELF-SPLICING INTRONS
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DOI：
10.1016/s0022-2836(05)80206-2
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发表时间：
1990-06-05
影响因子：
5.6
通讯作者：
MICHEL, F
中科院分区：
文献类型：
--
作者：
JACQUIER, A;MICHEL, F
通过比较序列分析和核苷酸替换相结合，我们表明，第二组内含子的活性中心的形成部分依赖于两个新的远程碱基配对相互作用。(1)组II内含子的最后一个核苷酸与连接结构域II和III的短序列段中的一个核苷酸形成单独的沃森-克里克碱基对。该碱基对的形成是3“切割和连接步骤的限速。(2)核苷酸3和4与结构域I的保守内环中的两个连续核苷酸形成碱基对。这种相互作用涉及5“和3”裂解步骤。考虑到这些新的信息片段之间可能的关系II组和核前mRNA内含子进行重新评估。
By combining comparative sequence analyses and nucleotide replacements, we show that formation of the active center of group II introns rests in part on two novel long-range base-pairing interactions. (1) The last nucleotide of group II introns forms a solitary Watson-Crick base-pair with one of the nucleotides in the short sequence stretch connecting domains II and III. Formation of this base-pair is rate-limiting for the 3'' cleavage and ligation step. (2) Nucleotides 3 and 4 form base-pairs with two consecutive nucleotides in a well-conserved internal loop of domain I. This interation is involved in both the 5'' and 3'' cleavage steps. Possible relationships between group II and nuclear pre-mRNA introns are reassessed by taking into account these new pieces of information.